著者

Shinya Hieda Konomi Ota Kisa Nagamine Hiroki Kobayashi Naohiko Noma

出版者

The Japanese Society for Plant Systematics

雑誌

Acta Phytotaxonomica et Geobotanica (ISSN:13467565)

巻号頁・発行日

vol.74, no.1, pp.47-51, 2023-02-28 (Released:2023-03-15)

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Endozoochorous dispersal of the invasive alien aquatic plant Ludwigia grandiflora subsp. hexapetala through waterfowl in Lake Biwa, Japan, is reported. Germination of seeds collected from the feces of waterfowl in Yabase, southern Lake Biwa proved them to be viable. It is necessary to be vigilant against the sudden appearance of L. grandiflora subsp. hexapetala in water systems where it is absent and to monitor its dispersal by waterfowl.

著者

Shinya Hieda Yuko Kaneko Masato Nakagawa Naohiko Noma

出版者

The Japanese Society for Plant Systematics

雑誌

Acta Phytotaxonomica et Geobotanica (ISSN:13467565)

巻号頁・発行日

vol.71, no.1, pp.65-71, 2020-02-29 (Released:2020-03-17)

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Ludwigia grandiflora (Michx.) Greuter & Burdet is an invasive aquatic plant native to an area ranging from the southeastern United States to South America. In previous reports, L. grandiflora in Lake Biwa has been identified as L. grandiflora subsp. grandiflora, a hexaploid subspecies (2n = 48) or L. grandiflora sensu lato. Species of Ludwigia sect. Jussiaea, are morphologically very similar. Morphological characters, especially floral characters and cytology (chromosome number) have been used to identify species and subspecies. In our study, the morphological characteristics of L. grandiflora in Lake Biwa substantially corresponded to those of L. grandiflora subsp. hexapetala (Hook. & Arn.) G. L. Nesom & Kartesz, a decaploid (2n = 80) subspecies. The chromosome number of L. grandiflora in Lake Biwa was 2n = ca. 80, the same as in L. grandiflora subsp. hexapetala (2n = 80). Importantly, L. grandiflora in Lake Biwa is not L. grandiflora subsp. grandiflora, but rather L. grandiflora subsp. hexapetala. This re-identification has implications for management in Lake Biwa, since the life history of L. grandiflora subsp. hexapetala has been studied in Europe.

著者

Shumpei KITAMURA Takakazu YUMOTO Pilai POONSWAD Phitaya CHUAILUA Kamol PLONGMAI Naohiko NOMA Tamaki MARUHASHI Prawat WOHANDEE

出版者

JAPAN SOCIETY OF TROPICAL ECOLOGY

雑誌

Tropics (ISSN:0917415X)

巻号頁・発行日

vol.14, no.4, pp.345-355, 2005 (Released:2008-09-30)

参考文献数

65

被引用文献数

7 9

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Seed dispersal by animals plays a crucial role in the tropics. Fruit-bearing plants serve not only as nutritional sources for frugivores, but also as seed sources for forest regeneration and as important foci for the re-establishment of other plant species by attracting seed-dispersing frugivores to their vicinity. However, opportunities for investigating the interactions between a diverse fruit flora and disperser fauna are rapidly disappearing in Southeast Asia. We observed the behaviors of 28 species of frugivorous visitors to 15 fruit-bearing plant species in a moist evergreen forest in Khao Yai National Park, Thailand, to determine their potential quality as seed dispersers. Behavioral observations included the frequency and duration of visits by each forager and their fruit-handling techniques. The highest numbers of frugivores were recorded at strangler figs, confirming their role as an important resource for frugivores at Khao Yai. Mammals and non-passerine birds spent significantly more time at food plants than did passerine birds. Our study provides a preliminary inventory of plant-frugivore interactions that is comparable to other study sites in Southeast Asia. Since fruit-frugivore interactions may differ among the forests, these kinds of studies need to be replicated at faunally intact forests, as well as depleted forests, in Southeast Asia.